This blog discusses current weather, weather prediction, climate issues, and other topics

Monday, August 12, 2019

Is Global Warming an Existential Threat? Probably Not, But Still a Serious Issue.

During the recent presidential debate, a number of candidates suggested that global warming represents an existential threat to mankind, and thus requires dramatic and immediate action.

Governor Jay Inslee has been particularly generous in the use of this term, but he is not alone. Kamala Harris, Cory Booker, Bernie Sanders and Elizabeth Warren have said the same thing, as have several media outlets and environmental interest groups.

Some of these folks also claim that the window for action on climate change is closing--Jay Inslee suggests that the next president will be the last able to take effective steps. Others suggest 10 or 12 years.

But are these existential threat claims true? That is what we will examine in this blog.
An existential threat is one that threatens the very existence of mankind. Something that is a simply a challenge or an inconvenience is not an existential threat. An existential threat must have the potential to undermine the very viability of human civilization.

As described below, global warming is a serious problem and its impacts will be substantial---but in no way does it seriously threaten our species or human civilization. And with reasonable mitigation and adaptation, mankind will continue to move forward---reducing poverty, living healthier lives, and stabilizing our population.

What do current climate models tell us? These models are run under specific scenarios of emission of CO2 and other greenhouse gases (see figure). In one, RCP8.5, we simply continue doing what we are doing, with escalating use of coal and oil. Not much renewable energy. Many believe this scenario is too pessimistic. Much more reasonable is RCP 4.5, which has modestly increased emissions through 2040, declining after 2050. I suspect this one will be closer to reality.

The implication of these emissions on global temperature is shown below based on a collection of climate models (CMIP-5). Under the extreme scenario, the earth warms by about 4C, but for the reasonable one (RCP4.5), global warming is about 2C (3.6F). This warming will not be uniform, being greater in the polar regions, less over the eastern oceans.

You will note the temperature rise in RCP 4.5 is relatively steady through around 2045 and then starts to gradually plateau out. No sharp transitions, no falling off of a cliff, no sudden catastrophes.

I have run a large collection of high resolution climate simulations over the Northwest, driven by the aggressive RCP 8.5 scenario. As shown for Seattle's mean annual temperature below, there is a steady rise, again with no sudden changes that would be hard to adapt to. Most NW folks will want to purchase an air conditioner for summer, but there is no threat to our existence, and winters will be more pleasant.

But what do official international and national evaluations project for the economic future?

First, let's check the conclusions of the highly respect Intergovernmental Panel on Climate Change (IPCC), which provides a consensus view of many scientists and nations. Their analysis (SR15, Chapter 3) quoted a paper by Yohe (2017) that found a U.S. GDP
loss of 1.2% per degree of warming, So with a 2 C global warming associated with RCP4.5, we are talking about a 2.4% loss of national income in 2100. Not a 2.4% loss from today's levels, but 2.4% less of the substantially greater income in 2100.

What about the recently released Fourth National Climate Assessment, a document heavily cited by the U.S. environmental community? Their analysis is that the damage to the U.S. economy in 2100 would be about a 1% loss (see below) This is not a 1% loss from the current U.S. gross domestic product (GDP), but a 1% loss of the substantially great GDP in 2100. We will be much richer in 2100, and will lose 1 % of our GDP because of global warming. Doesn't sound like the end of civilization, does it?

W. D. Nordhaus, who won a Nobel Prize in economics for his study of the economic impacts of climate change, examined a large number of studies regarding the impacts of global warming on the world's economy (see below). He and his co-author (A Moffat) found that a 2C increase in global temperatures would result in 0-1% damage to the world economy in 2100. Doubling the warming would only increase the damage to around 3%. Again, no existential threat.

Reading these numbers and considering the many reports backing them up, there clearly is no existential threat to either the U.S. or mankind from global warming, leaving one to wonder why are so many politicians, environmental activists, and lots of media are spreading this existential threat line.

And the above studies are not really considering the potential for major technical breakthroughs in energy generation (e.g., fusion), renewables energy sources, or carbon removal form the atmosphere (sequestration). I believe that such advances are inevitable, just as no one in 1950 expected that 2000 would bring personal computers, cell phones, and more.

You also have to wonder whether scientists, politicians, and environmental folks really believe the existential threat warnings they throw around. Many talk the talk, but most don't walk the walk.

Presidential candidates with little chance of securing the nomination are flying back and forth around the country, resulting in enormous carbon footprints. Climate scientists fly more for work and pleasure than anyone. Many environmentalists oppose nuclear power, one of the technologies that could produce massive carbon-free energy. And several local Washington State environmental groups opposed a revenue-neutral, bipartisan carbon tax initiative (I-732).

Global warming is a real issue and we are going to slowly warm our planet, resulting in substantial impacts (like less snowpack in the Cascades, increased river flooding in November, drier conditions in the subtropics, loss of Arctic sea ice). But the world will be a much richer place in 2100 and mankind will find ways to adapt to many of the changes. And there is a good chance we will develop the technologies to reverse the increasing trend in greenhouse gases and eventually bring CO2 concentrations down to previous levels.
Global warming does not offer an existential threat to mankind, and politicians and decision makers only undermine their credibility and make effective action less likely by their hype and exaggeration. And their unfounded claims of future catastrophe prevents broad national consensus and hurts vulnerable people who are made anxious and fearful. And just as bad, all this end of the world talk results in folks turning away from the issue, both out of fear and from intuition that a lot of hype is going on.

Hi Cliff,I hope you would consider giving your perspective, at some point, on the issue of positive feedback loops, especially in regard to methane release from melting permafrost and frozen arctic seabed. Also, of interest to many is how the change of arctic albedo and change in water current temps in the arctic may affect the scenario beyond the arctic.From my amateur observation, it looks to me like we are following the high CO2 emission scenario, and will do so for 10-20 yrs. After this period the emission will likely stabilize or significantly drop, primarily due to fossil fuel depletion, and secondarily to policy change and renewable deployment (such as electrification of transport).

Thanks Cliff - I appreciate your explanation of the issue in an understandable and reasonable manner. In your opinion, what is it that we can do to offset our impact on the environment? I'm not interested in what Inslee, Cortez, Warren, et al have as a solution, IMO they only want more money and power and I will fight them tooth and nail. TIA

"And with reasonable mitigation and adaption"...well, you bit off a lot with that statement, Cliff. Yes, we are spectacularly adaptable as a species. "Reasonable mitigation"? We have difficulty with that on a single court case much less arriving there in issues between nation-sates and humanity as a whole. I don't see reasonable mitigation solving the problem of a carbon-rich atmosphere. Time will tell. But the last 50 years is not encouraging as far as that goes. I do appreciate your perspective.

Isaac... many of the feedback loops are in the models--they are fully interactive ocean, atmosphere, cryosphere models. The high and low scenarios are very similar for next 20 years....and then they diverge. ..cliff

Curt... global warming is only one environmental issue, and perhaps the easiest to solve. Sustainability is the key.... maintaining the soils, water quality, air quality, etc. of our planet...and getting our population under control.. We need to aggressively follow the nuclear option as we use renewables sources as much as possible. And we need to work on adaptation and resilience...cliff

I am so glad to hear a credible climate scientist admit that we need to pursue nuclear power in A BIG WAY. A few Teslas, Nissan Leafs and a bunch of hybrids won't amount to a drop in a 50 gallon drum. I am a forester of nearly 45 years and I can tell you that I have seen absolutely no, and I mean zero, change in west side of the Cascades forests over that period of time. I would like to see wind turbines exposed for the feel good, insignificant factor that they are as well. And you are right: the IPCC, Governor Inslee, and many other have cried "wolf" much to often... when they are not running around like Chicken Little that is. And the hypocrisy is mind blowing amongst the most strident, such as the Hollywood crowd.

Unfortunately, lower snowpack and "more comfortable winters" (I happen to like the temp to be below freezing for part of the winter) means less water, creating more strain on fisheries, agriculture and general population, as well as rising sea levels. Economically, our winter sports will have to change, no more skiing. I am glad I took my kids to see glaciers, because I doubt their kids will ever see them.

Please explain how lower snowpack will result in higher sea levels. Please cite credible sources. I agree on the glaciers, but they were shrinking before global use of fossil fuels. Some of my favorites are nearly gone now, but I am far from convinced of the primary cause being anthropogenic temperature increases. Those glaciers once spread down to the Alvord Desert in SE Oregon. Climate has never been static.

J Schmit. The regional will actually have a bit more precipitation under global warming. So to adapt, we may have to store more water...which means more reservoir capacity, particularly for eastern WA. My point is not that global warming is good...it isn't, but that it is not an existential threat to our survival. You don't fight a war saying the enemy is twice as strong as it is. You lose wars that way...cliff

Cliff, the divergence in models after 20 years is important. There is a lot of uncertainty about projections, and that uncertainty goes both ways. Would you agree that there is a possibility that ice sheets could collapse, and that positive feedback loops will push us into a new extra-interglacial climate pattern? What is your critique of the hothouse earth scenario (www.pnas.org/content/115/33/8252)? You are still making a lot of optimistic assumptions about what we will choose as a society. You're also focusing on wealth of the United States as a proxy for social health. That's a eurocentric perspective that doesn't acknowledge the very real existential threat to millions of people living in low lying areas and the tropics (which don't require much of a temperature increase to become uninhabitable, nor the massive migrations of climate refugees that will dwarf any refugee crisis we've ever experienced.

You seem more intent naysaying the concerns of the environmental community with a suite of optimistic assumotions than scientifically discussing the range of severity of possible impacts.

You seem more intent naysaying the concerns of the environmental community with a suite of optimistic assumotions than scientifically discussing the range of severity of possible impacts.

You use a lot of fancy words, Colin, yet I suspect that you may be lacking in a fundamental science background. What precisely, are your qualifications to, as you say, "scientifically" discuss the range of severity of possible impacts. Personally, I am only concerned with Probable impacts.... range of severity of Possible impacts basically means from absolutely NO effect to irreversible global annihilation of all life. On how many issues do we consider the absurdly improbable if we are believers in scientific method?

Cliff...I greatly enjoy your blog, but I have to respectfully disagree with you here. To assume that we will find a way out of this using technology and to just assume that humans will basically "do the right thing" is akin to burying our head in the sand. It seems like every time a new model or new data comes out it shows that we are on the "worst case scenario" trajectory. Based on human nature AND the current political attack on environmental regulation, what makes you realistically think that we will NOT continue to follow that trajectory? Yes, we can all hope for fusion and carbon capture and technological advances to save us from a worsening future...but what if those things DON'T work out? While I don't agree with climate extremism and maybe climate change is not an existential threat in that it will wipe humanity off the face of the earth, but it IS a threat to the existence we currently know...including millions if not billions of people that live in poverty in the areas that potentially will be hardest hit by climate change. We HAVE to be proactive in doing what ever we can NOW to change and adapt because even if carbon emissions ceased today, there will be a 10-20 year lag as the climate adjusts to the current CO2 levels. The alarm bell needs to be rung.

AndyGross over reaction by leftist politicians to a non-existent threat (climate change) is the actual existential threat.

We have 78 years of experience with rising CO2 levels and an intermittent, slightly rising global average temperatures, of which the IPCC claims "over half" is man made (meaning up to half is NOT man made), with no scientific proof their "over half" wild guess is true.

Cliff Mass fails miserably to explain all the (imaginary, actually) harm done by the global warming in the past 78 years (an average global warming rate of less than +1 degree C. in a century, from 1940 through 2018).

In fact, adding CO2 to the atmosphere in the past 78 years has been good news, 'greening' the planet, and is likely to be additional good news in the next 78 years.

We don't have to do anything about fossil fuels, except to make sure they are burned with modern pollution controls, because adding CO2 to the atmosphere is not a problem, it is a blessing (ask any greenhouse owner about CO2 enrichment systems).

When the current Holocene inter-glacial ends, and the climate gets a lot colder, people living on this planet will miss the "good old days" of mild, intermittent global warming, when the upper half of the Northern Hemisphere got warmer in the coldest six months of the year, mainly at night.

Its clear that plants are having a fabulous time with more CO2 in the atmosphere. NASA satellite imagery shows a dramatic greening of the plant over the last few decades (https://www.nasa.gov/feature/goddard/2016/carbon-dioxide-fertilization-greening-earth).

Higher agricultural productivity is another benefit, allowing us to produce more food without the need to use natural forested land for agriculture.

Fauna living off plants will have more food and should do well. Animals which feed of the increased herbivores will have more food available.

Dean it is true that due to increased CO2 concentrations there has been an increasing rate of plant growth. However, if you follow the research deeper, it becomes clear that even increased rate of biomass growth is not offsetting growing greenhouse emissions. Further, the increase in planetary greening is ALSO being offset by global deforestation, which is absolutely one of the most under-discussed mechanisms by which we are now growing beyond 400ppm atmospheric CO2.

Sir, how can climate models suggest anything about any species? That is a debate for biologists, not climatologists. This is a MUCH more complicated issue, and, even with the species of trees and plants that I study the most I could not begin to say with any confidence what the effects of a 2-3 degree change might be. I would GUESS that natural selection will do what it has always done and that those individuals with the most beneficial genetics in regards to the disturbance agent *in this case, temperature, will experience a relative increase in abundance. The reply Dean S gave is bunch of voodoo ecology mumbo jumbo

Thank you for your honesty, Cliff. This sort of thing is dangerous to say. I know that your honesty has already cost you, but you should also consider what it brings. I have essentially been a human-caused-global-warming-denier. The histrionics of some many so-called experts encourages me to doubt them all. You don't need fear when you have truth. Their chicken little sky falling meme does not remind me of the true scientists and experts I know.

Your calm and honest assessments, however, are far more convincing then their fear-mongering. (Here's looking at you Inslee.)

Other areas of the country and world will be affected disproportionately. Are we prepared to deal with the results (displacement, food scarcity, water scarcity, migration) in a humane way? Look at how we're handling things currently...

This is a political problem, not just a science and engineering problem. And our solution should be equitable.

The more stress you put into a system, the more chance of catastrophic failure. Given the current state of our political system, how can we trust that it will handle that?

This is why I consider climate change an existential threat. Sure, technically some of humanity will likely survive, but how much? What proof do we have that we can handle these stressors humanely? The potential for mass immiseration and suffering is horrifying.

I find this idea that climate change is going to selectively target poverty areas to be fascinating.... are we talking about the sea rise thing, or what? As far as I know,the wealthiest people tend to live on the coasts. So we must be talking about deserts and the assumption that many millions of poverty stricken folks live there? And a change of temp. from 102 degrees to 105 or so would mean the end for them? This is a new one I've seen a lot of this last year.... usually with no viable explanation that is free from hysteria. And don't hang the "hater"moniker on me either.... being rational does not equate to hating people. In fact, my experience has been that no one hates people more than radical environmentalists.

Great post Cliff. This was obvious to anyone with a reasonably curious mind. It has always been about a political pathway for Socialism and never about any real threat. Take the Puget Sound. Any perceptible change anywhere along the Seattle waterfront in the lifetime of anyone alive today? No. At best we are talking a few millimeters a year of sea level change. Not part of any human timescale. And definitely nothing that constitutes alarm in any way. Alarm is a word reserved for the immediate. Climate Change is about adaptation on a 100 year time scale and beyond. Humans will be fine, and much better off without Socialism too.

Sea level rise is far from the only threat associated with a warming planet. Drought, flood & wildfire are 3 of many phenomena that will increase in frequency as the planet warms. When it happens, the decisions we make today will reverberate over the coming decades. In a world with billions of refugees we will end up with either eco-socialism or eco-fascism. Let's pray for the former.

OK. I am a former forest firefighter and fire behavior specialist. I keep hearing this thing about more wildfires... where is this coming from & how can you reasonably predict this? When you build 4,000 square foot mostly wood homes in areas that have always had a 20-50 year extreme fire event history, you are going to have trouble. Incredibly, there are areas in southern California where the homes have cedar shake roofs!! You seem to be a bit of a Kool-Aid drinker... what are the "many other phenomena" you infer? Please cite credible sources.

Andy, you are correct. The "feel good" narrative that says we're all going to start holding hands and do the "right thing" is an old broken record and it doesn't work. People like to say they are on board with that stuff, but when the congregation goes home they don't actually behave that way. The average human will go along with just about anything - just so long as there is no downgrade in their creature comfort or their personal financial status. It's going to take a "bottoming out" before things turn around and that won't happen for centuries.

"You also have to wonder whether scientists, politicians, and environmental folks really believe..." I believe they do believe. My question is what makes people so obsessed with climate issues, when the biggest issue in my opinion is habitat loss and the collapse of human dignity. It's as if people gravitate to an unsolvable problem, one that requires geo/social-engineering at a level that makes us believe that we actually do have some control over a extremely biologically and chemically complex stellar object with a diameter of 8,000 miles. I argue that the deeper issue is a creepy desire to have some deep techno-utopian command of both the planet and the people. It's a radical desire for control of the earth in a way never envisioned before: Deep Globalism. And the great irony is that oil, being such a limited resource, will be gone before we know it and the carbon footprint will fade as the photosynthetic greenery returns to the face of the earth, as the oceans continue sequestering the gas we smoked off into the atmosphere during the end of the Industrial Age.

As much as I appreciate this perspective being discussed, I have to say the entire premise is flawed in the sense that this article downplays the threat of climate change because it technically doesn't meet this definition of the buzz term "existential threat". Why is this an important argument to make when the fact remains that large populated areas are likely to be strained with water and agriculture, resulting in human suffering on a large scale? The message of this article is "politicians use hyperbole" (This isn't news to anybody, but it is a problem indeed), but the effect is "We shouldn't take climate change as seriously as politicians say we should".

It's going to take a great effort simply to keep emissions below the 8.5 scenario. Petroleum is so packed with energy, and so relatively cheap, and so profitable to sell, that the pressure to use it will be high and constant. If people look at your analysis and say, "Oh, good, we don't have to worry about it now," we will surely be heading for the worst-case scenario.

I think that people love making it all about US politics when it is a global issue that may not threaten to wipe out humanity - the existential threat scenario - but is much bigger than some political "socialist" propaganda. For me the big risk is not in the climate alterations threatening our existence, but in the upheaval that may be caused by the extremes impacting populations in "localized" areas that are beyond their capacity to cope. Increased stresses on regional populations can lead to more forced migrations - and the world's attitudes towards refugees is not a good one already. It can also create local wars and terrorism that threatens to spread. The existential threat may not be in our physical ability to survive the climate changes, but in our ability to survive the risk of the stresses put on populations that cause them to lash out in desperation. One terrorist nuke, or big war between India and Bangladesh/Pakistan as the peoples in the deltas seek higher ground put nukes potentially into play, for example.

Cliff, I tend to agree with you that using "existential threat" to describe climate change is problematic. But you are essentially saying that projections of climate change -- based on physics -- are more uncertain than predictions of a technological deus ex machina, based on wishful thinking with a bit of the "dismal science" thrown in. That's ridiculous. I'll take physics any day.

Mitigation can do a lot, probably even enough. But not if it is not pursued. There are political movements across the world dedicated to taking out every ton of coal and every barrel of oil. They have a lot of power, and our current administration is full tilt in support of bring coal back and continuing subsidies to petroleum. Uncounted in the last is the $3 trillion and counting for wars in the mid-east.

A while ago I remember you mentioning that you may post a blog about how solar activity affects the climate. It would be interesting to hear your opinion whether the colder temperatures in Europe in the 17th-18th century were really related to the Maunder Minimum and whether we are headed towards another solar minimum that could affect the climate. You mentioned that it is not likely, but it would be interesting to hear your arguments.

It's good to neutralize some of the unwarranted fear generated by extremism and replace it with the best known factual projections. Rational minds can better consider the hierarchy of issues and more effectively pursue a productive plan of action.

World's #1 problem is the rate of population increase. Not currently political correct to talk about.Global warming is probably #2 ... massive coastal infrastructure rebuilds ($$$) and most probably human migrations as some lands come unproductive and/or inhabitable. Agree with Cliff's major points ... the world isn't going to end. But global warming is going to be infrastructure costly, and nobody has any real solutions to peoples who are going to be displaced. .

Eric (Steig)..you are misunderstanding me. The best estimates by the IPCC, Fourth Assessment, Nobel Prize winning economists find only a small economic hit for the US or globally. This is NOT an existential threat. We are failing to use valuable technologies (e.g., nuclear) and certainly more technological advances are coming...that is for certain. Happy to talk it through with you..cliff

I really enjoy your blog, but I disagree with you here on a couple of key points. Steve Keen has done some excellent work picking apart the "damage function" developed by Nordhaus on which these claims of % reduction in GDP per degree of warming are based. They are based on fitting a smooth quadratic function through some highly questionable (and noisy) data points, and then extrapolating that far past the available data. It does not allow for the possibility that the impacts may become more severe as the world warms. If you used the same technique in meteorology, you would completely torn apart during peer review. https://www.themintmagazine.com/nordhauss-nobel-prize-is-safe-but-the-world-isnt

Secondly, you are using a very US-centric metric for assessing the impact of climate change. Most of the world's population are far more vulnerable to changing climate

"Secondly, you are using a very US-centric metric for assessing the impact of climate change. Most of the world's population are far more vulnerable to changing climate"

I keep hearing and seeing this and wonder what the source is. Of course, if you are a poverty stricken nation - and the IPCC is basically a NATO organization - and there is a chance to get some serious money, you are going to distribute biased information that might help you get some of the money. I work with computer models... in my case they are all related to forestry. They are quite simple models, really, and do not rely on any proxy data - only real time data collected by forest technicians and, in some cases, remote imagery such as LIDAR. What has always amazed me is that, even with robust data input, they are often wrong. So I am very skeptical of models that are substantially more complex, and frequently rely on proxy data (the dendrochronology assumptions are extremely flawed and show the folks doing the models don't understand much about tree physiology) to arrive at trends and predictions which are accepted by so many "scientists" as highly, or even reasonably, probable.

But shouldn't we prepare for the worst? I'm not an adherent of this approach. We should prepare for the reasonably probable. That is why casinos always win, from a cumulative standpoint. And they always will.

But, if someone can point me towards an unbiased longitudinal study that does not rely on proxy data and that specifically can explain how and why as financial status decreases, negative effects of climate change (a term I wish would be replaced since climate has NEVER been static) increase, I would truly appreciate the opportunity to objectively look at it. Heck, it would not even need to be a longitudinal study. Just anything that makes a convincing case would do.

Michael Snyder: Food production has never been higher and never have such a high % of human been as well fed. Climate change has been going on for 30 years and it is not producing any crisises driving immigration.

Cliff, thank you for writing this post. I have long believed that climate change is one of many environmental issues that need addressing (soil degradation, overuse and pollution of fresh water, habitat loss, deforestation, etc.). The single-minded focus on climate change has always baffled me. We will be sorry in the very near future that we overlooked the root causes of water shortages (policy, greed, corruption, etc.) around the world because of the obsession with climate change.

Excellent post Dr. Mass and greatly appreciated. Additionally, there is one very significant benefit to higher CO2 levels that is not mentioned and that involves the greening of the planet which NASA has confirmed and is also evident in higher crop yields as reported by the USDA. The real existential threat occurred about 20,000 years ago when CO2 levels dropped to about 180 ppm. At 150 ppm live as we know it would cease, because many plants quit photosynthesizing. With each glacial period during the past 2.5 million years, CO2 levels have been trending down. A continuation of this trend would spell doom.

The plant community is loving the increase in CO2 levels and will continue to thrive and increase growth rates to levels greater than double today's CO2 levels. We will have run out of fossil fuels long before we get to that point.

Most of the Democrats who now hold state and federal elective offices in California, Hawaii, Oregon, and Washington strongly support the Green New Deal. They will have much greater influence in Washington DC if Democrats gain full control of the federal government in 2021.

In its current form, the Green New Deal has a target date of 2030 for a 100% carbonless economy. The 2030 target is an opening bargaining position. Over the next several years, the GND's goal posts will gradually shift back towards President Obama's original target of an 80% reduction in America's carbon emissions by 2050.

Even with a target date of 2050, it is impossible to reach an 80% reduction without imposing considerable sacrifice on the American people in the form of strictly enforced energy conservation measures combined with steep increases in the cost of all forms of fossil fuel energy. For one example, per capita consumption of electricity in America must drop to half of what it is today.

Furthermore, it is impossible to reach 80% by 2050 without a massive commitment to nuclear power, and to manage the energy market transition in a way which leaves no choice but to sacrifice the benefits of market competition with natural gas in keeping a lid on nuclear's costs.

Green New Deal advocates are likely to be in full control of the federal government in 2021. They will then be forced to put real meat on their GND energy policies. Will their 2021 plan be something new and different? Or will it be a rehash of Barack Obama's plan updated with Green New Deal rhetoric, but containing little else of real substance?

If Democrats are truly serious about reducing America's GHG emissions, they must do what current law and past practice demand they do. They must give the president and the EPA full and complete responsibility for the tough job of reducing America's carbon emissions 80 percent by 2050.

As a starting point for other comments to follow, I am reposting a plan to reduce America's GHG emissions 80% by 2050 using the Clean Air Act augmented by existing national security legislation.

This plan is similar to the one that was being pushed a decade ago in 2009 by 350.org. In this new version, the original 350.org plan is augmented by a system of carbon pollution fines which is the functional equivalent of a legislated tax on carbon.

Moreover, if carbon pricing combined with massive new spending on green energy projects doesn't prove to be fully effective, the updated plan adds a provisional system for imposing direct government control over the production and distribution of all carbon fuels.

These are the major phases of the plan:

Phase I: Establish a legal basis for regulating carbon dioxide and other carbon GHG's as pollutants. (2007-2012. Now complete.)

Phase II: Expand and extend EPA regulation of carbon GHG's to all major sources of America's carbon emissions. (2021-2022)

Part 2 of this extended comment lists the details of the above plan. Part 3 describes past efforts at creating a legal foundation for EPA regulation of all of America's carbon emissions. Part 4 examines the moral imperatives climate activist politicians face if the dangers of climate change are real and are severe. Part 5 examines the intersection of climate action moral obligation with climate action policy.

-- -- -- -- -- -- -- --

Full Disclosure: I post as 'Beta Blocker' on WUWT and on Judith Curry's blog.

I agree. Totally: Population growth is the biggest issue. Somehow, since Paul Ehrlich's book came on in the 70's, it has gotten to be politically incorrect, even among environmentalists, to discuss it. I suspect this has to do with race, since the less advanced cultures have higher birth rates and coincidentally are "nonwhite". But the sooner we face the issue, the better.

Agree. Why does the Malthusian Theory continually crop up? It's steeped in depression and disharmony. If those factors aren't present then create them through policy. I prefer the Optimum Theory it makes more sense.

The conservative approach (by definition of the word) would be to organize our society to prepare for the changes that are coming at the same time as we look for solutions to mitigate the extent of the changes. I'm hopeful the majority will come to see this as the way forward. Surely we are capable of improving our world, not just hoping that it only degrades slowly.

Yup, stabilizing the Human population at a level lower than it is now will solve many issues and is considered the number 1 solution for climate change. In a constant growth economic model it might not pencil out, though. Since almost everything is leveraged on some kind of future growth, there has to be either more people being consumers, tax payers and workers or everyone has to be vastly more productive per capita.

There is still the aspect of consumerism and the throw away culture that is being perpetuated. Tearing raw materials out of the ground for a quick dopamine rush at a 30% off sale so that they can just be dumped in the ocean down the road is not a good long term solution other than for corporate bottom lines. For every billion people added to the world, that damage goes up exponentially.

Personally, less people would be fantastic. Just go sit in traffic in any city during any time of the day it seems. Or witness the lines of people going up Mt Everest. Can't really seem to find anywhere to completely escape people. They are everywhere, acting their usual stupid selves.

Its an issue that may solve itself in the fact to raise up a kid in the modern age costs a truckload of money. To give to them all that society demands such as tech, college educations, sports etc apart from the usual room and board is monumental. Of course the oldsters living into their medical system straining 90s and SS/pension fund managers get nervous about that.

I disagree with this view. Technology will help us move forward even as the population increases. 95% of the world population occupies 10% of the land mass and the land mass is only one third of the total surface of the Earth. You have to be careful with how you "stabilize" population as you may end up with an aging population. That is not how nature designed the cycle of life. Challenges for the future will be how to reduce or even eliminate pollution, and find sustainable sources of food, water and energy. With enough political will, these challenges can be resolved.

I agree with you about the cost of higher education. I believe the solution is to focus more on vocational training. The problem is that there is a lot of politics involved because universities in America are run like businesses. On top of that, you can no longer default on student debt thanks to one of the previous (democratic) presidents. There are too many entities including the banks that profit from the current American university system.

While your argument is successfully played out at the macro level you analyze, a more problematic outcome may be in store for a micro level of analysis. Taking some of the projections from the CIG for alteration in precipitation patterns, along with increases in stream temperature from the warming air temperatures and reduced summer flows, not to mention other forms of habitat destruction resulting from more people moving to the NW to escape environmental damage in other regions, it is a very real possibility that salmon may be extirpated from Puget Sound this century. This may be exacerbated by the devastation of their food supply due to the impacts of ocean acidification brought on by climate change and increased nutrient runoff. Suer there may be salmon in Alaska, but perhaps not here in Puget Sound.

What does this do for the livelihood and culture of Tribal people who are dependent on the fish for their well being? They cannot simply move to Alaska; their rights to fish are based on our land and waterscape right here. At this scale the existential threat to their traditions and culture are very real. Sure, human civilization may not be gone but the culture that has persisted in the northwest for thousands of years may be.

This planet has had 325 years of experience with mild, intermittent global warming, since the coldest period of the Little Ice Age, in the late 1600s.

The last 78 years, of those 325+ years, 1940 through 2018, included increasing man made CO2 added to the atmosphere.

Those 78 years harmed no one.

There is no logical reason to claim the next 78 years of adding man made CO2 to the atmosphere will be bad news.

Our planet has been 'greening' for the past 78 years.

Winter nights in Alaska are warmer.

Where is the bad news?

It appears the bad news from global warming is ALWAYS in the over-active imaginations of leftists, and other people who believe in the always wrong predictions of climate computer games, and other climate fairy tales.

1) Everyone can be gainfully employed at the very least. 2) Everyone (as in whole planet) doesn't aspire to be a wasteful American consumer.3) Everyone has opportunity to decent healthcare and education. 4) Everyone can get clean water, decent food and breathable air. Maybe even a roof over their heads.

Some would probably brand that "socialism". It doesn't have to be that taboo on our culture but there has to be opportunity to achieve those things. Plus, clean air, water and decent food? That should be a right. Not something earned or something at the mercy of the markets.

That is from the perspective of before robots take up the mantle of doing everything that is currently considered "work". Its not the folks that George Carlin told jokes about that are going to take yer job. Its automation in the form of Robots and AI. Even so called "creative" work can be done by a learning AI in due time.

Looking on the streets of Seattle, the tent cities are already inferring that we either have surplus people and/or the system can't cope with them. Its not just Seattle. Its migrants crossing the Med in overloaded barges or even Central Americans trudging through Mexico to make a run at crossing the Rio Grande.

So yah. We don't really know what to do with the people we have, let alone what to do with billions more. Perhaps at the very least get the population stable and practice decent replacement. It doesn't make sense to punch out litters of kids that might not have much of a future and in turn just end up on some kind of public assistance dole or worse living on the street like the population in "Soylent Green". Quality over quantity works best these days and that requires folks have access to those aforementioned things BEFORE the robots redefine what "work" is. Long story short is the system needs some serious tweaking to accommodate more people. Maybe that should be proactive instead of reactive?

If the Green New Deal can't deliver on its promises in quickly reducing America's carbon emissions, climate activists already have the authority of the Clean Air Act to rely upon should they decide to use it.

Cliff: Though I general agree with most of the thoughts in this post, there is a reason that many will disagree. Though it isn't always obvious, their reasoning begins with these words:

"As described below, global warming is a serious problem and its impacts will be substantial---but in no way does it seriously threaten our species or human civilization. And with reasonable mitigation and adaptation, mankind will continue to move forward---reducing poverty, living healthier lives, and stabilizing our population."

Many people, particularly the affluent (and ivory tower academics?), believe our current lifestyle is already unsustainable. Even if GHG-mediated climate change were not coming, they would fear that their descendants were going to be worse off than they are due to over-population, resource depletion, pollution, etc. Such beliefs predated climate change. Given the expectation that these problems were inevitably going to make it challenging for their descendants to even maintain their current lifestyle, it would be immoral to add to even a modest amount of climate change to the problems future generations face. The price of limiting CO2 emissions is irrelevant, when saving the world for generations is a moral imperative.

The developing world, on the other hand, wants to enjoy the many benefits the developed world obtains from an energy-rich society. The same thing is true for the non-affluent in the developed world. It is impossible for leaders of the developing world to plan for a future with limited and/or extremely expensive energy. The developing world wants to emulate China and grow GDP at 6% for the next three decades. Coal has been and is likely to continue to be the cheapest path to the energy needed to drive that GDP growth. GDP-growth is the primary moral imperative, even at the cost of immediate air and water pollution, much less the delayed problem of climate change. Their much richer descendants can deal with the consequences of rapid development, just like Americans dealt with the problems of water and air pollution beginning around 1970.

The Ramsey theorem provides a mathematical framework for understanding these to perspectives. The Ramsey theorem says the optimum discount rate for all kinds of investment is proportional to the future economic growth rate. Mathematically, if you expect little or no future economic growth, you should apply a low discount rate future damage from climate change and be willing to pay a lot today to reduce emissions. If you expect robust economic growth, you would apply a high discount rate to damage from future climate change and would be willing to spend very little to help your much richer descendants avoid the problems you have left behind. It is impossible to come up with an economically rational GLOBAL strategy for limiting emissions, because we have very different expectations about future economic growth. The developing world will be happy to follow a low carbon strategy as long as the developed world is willing to pay for it. Thus the INDC from developing countries are based on business as usual (robust economic growth) and contingent on foreign aid that everyone knows won;t be coming. In the US, Republicans believe in a future with high economic growth and dramatic technological progress more than Democrats. Even if climate scientists had an unambiguous value for ECS and economists had the same from future damages from climate change, we still would't be able to agree upon an economically rational program for reducing emissions.

The late Dr. Carl Sagan believed the only way that population growth can be controlled is for the entire world to industrialize. He also recognized that if the entire world industrializes, then humanity must accept the risk that other problems with increased pollution and environmental degradation might emerge. It was his opinion these problems can be dealt with as they appear, and that the benefits of world industrialization are well worth the additional risks.

Low birth rates associated with increasing prosperity are already a reality everywhere except Africa. The developed world is below ZPG. Economic growth in less developed countries outside Africa has produced dramatically falling birth rates that suggest that the entire world outside of Africa will soon be at ZPG. This is admittedly a controversial topic. Some still cling to the idea that world population in 2100 will be 11 billion and climbing. Others citing newer information say world population will peak in 2050 at 8 billion and start falling.

Since climate science was hijacked for a political agenda, most of the information that reaches the average person comes from sources that have an allegiance to the politics vs being committed to authentic science. Thus, the inability of many people, educated about a fake climate crisis in this manner to put it into proper perspective based on the realities that you described.

One should also note that over 100 scientific studies show that it was this warm 1,000 years ago during the Medieval Warm Period and that warmth was found to be global. Similar to even warmer conditions existed during the Roman Warm Period, around 2,000 years ago and the Minoan Warm Period around 3,500 years ago. The Holocene Climate OPTIMUM between 9,000 and 5,000 years ago was MUCH warmer than this in the higher latitudes.Up until climate science was hijacked, the word OPTIMUM was used to describe conditions for life on this planet when it was warmer than this.Now, it's a climate CRISIS......despite the planet greening up from a beneficial gas, violent tornadoes being reduced from the meridional temperature gradient and the fact that cold kills 10 times more effectively than heat.Life still needs to go dormant or hibernate or migrate south in many areas during the Winter to protect itself from the real threat and find food that comes with warmer temperatures.The current atmosphere holds around 6% more moisture than the one of a century ago, since warmer air holds more moisture, so heavy rain events and flooding have increased.However, going back to that atmosphere with CO2 starved plants/crops(100 ppm less than today) and colder temperatures would result in food production losses of around 25%. This would result in a massive deficit in supplies to feed the massive world population as it approaches 8 billion people. One can reasonably estimate that within 3 years with such deficits, close to 1 billion people on this planet would starve and rationing from the disparity between today's demand and the supply from growing crops from last centuries climate/CO2 levels would cause prices to at least triple.....until an equilibrium was established.We should also note that sea levels are rising at just over an inch/year and that climate model projections, which do help us to see potential outcomes, have a wide range/spread and so far, they have mostly been warmer than the observations, not the other way around. So ramping up the alarmism with more extreme views(it's worse than we thought/predicted) to scare people into taking political actions is not scientifically justified.